Rotary drying apparatus



H. A. MARsToN www 1mm@ APPARATUS l Filed ,TullyA 22 in.. L. i

forward flow of the material.

Patented Nov. 22, 1927.

UNI'IEDk STATES HZOBACII ARTHUR MARSTON, OF SUTTON, ENGLAND.

ROTARY DRYING APPARATUS.

Application led July 2v2, 1927, Serial No. 207,823, and in Great Britain June 8, 1928. 'i

Drying apparat-us of the rotary druin type is already known in which the drum is divided into internal cells, but in such apparatus no means is provided whereby an. intermediate mixing chamber intimately mixes and disintegrates the partially dried material by causing saine to pass through the drier at a non-uniform rate.

The present invention remedies the abovemention'ed defect. The invention has/for its object to provide an apparatus of the rotary drum type and supported by rollers at both ends, the drivin means being provided by an external toot ied crown meshing with .a driving gear wheel'. The rotary drum is divided into cells by longitudinal partitions and is provided with one or more intermediate enlarged mixing and disintegrating chambers or portions, in which chamber or chambers an intimate mixing takes place be tween the hot gases and the material passing through the dryer.

In the accompanying shows, by way of example, struction of the invention,

Figure 1 illustrates a sectional elevation of the apparatus, 'f

Figure 2 is a corresponding plan view, and

Figure 3 is an enlarged vertical cross-section on line A-A of Figure 1.

The apparatus comprises a drum orcylindrawing, which a form of conder 3 having an enlarged section or sections p formed with a central baffle 4 of frusto-conical or other suitable form having, if desired, spiral vanes or guides 5, the drunr or cylinder being supported at both ends by rolling crowns 6 turning on rollers 7. A thrust roller 8 at either end, engages with the side flange of the rolling crown 6 and prevents any longitudinal movement of the drum, and an external .toothed crown 9, driven b a pinion 10, provides for the rotation o the drum. The end of the drum or cylinder adjacent to the above rotating device 9, 10, isengaged in a hood 11 which ,supports the feed chute 12. j The drum or cylinder 3 is enclosed in a masonry envelope 13. A furnace 14, which may operate with pulverized coal, heavy oil or gas, is provide at the side. The drum 3 is provided with dividing partitions 15 forming internal cells 24, and also one or more intermediate enlarged mixing chambers 16, and said drum is inclined from the horizontal to permit the The material,

-when discharged from the drum which carry t is carried away by a screw conveyor or a chute 17.

'lhe operation of the apparatus is as `follows The hotv gases produced by the furnace 14 pass through an opening 18, then circulate, lirst all round the outside of the drum or cylinder 3 and between the latter and the Inasonry envelope 13 and then entertlie inside of the drum by means of the ue 19 where they iinpinge on the material to be dried and drive oil' the moisture therefrom. The hot gases, after passing through the discharge end of the drier, are'retarded and in part di:

' verted to the interior surfaces of the enlarged sections by the baille 4 and by the, vanes 5, the retardation increasing the heat4 transfer between the gases and the material.y The hot gases arev also subjected to a rotary action by the rotation of the buckets or scoops 20. The form ofthe baille 4 and the fanlike action of the bucks/ts or scoops 20, will create eddies that will still'furtlier retardvthe flow of the hot gases through the drierv and cause a still further reduction in the temperature of the hot .gascs. The deflected hot gases, after passing over the baffle 4, will expand in the enlarged portion of ,the intimate mixing chamber 16 and again give up further heat before passing through the feed end'of the drier by way vof the tiue or fan 21 to the chimney 22, a portion of thel hot gases also assng through the baiile 4,"and the tube 23 to the fan 21. The material to be treated is fed in the undivided portion or hood 11` of the drum by the chute 12 and is divided in the internal cells 24 and travels forward, by reason of the inclination of theldrum until it reaches the intermediate mixing chamber 16. The said chamber subjects the partially dried material to lvarying frictional forces due to its varying sectional area, such varying frictional forces tending to disintegrate any'material which may have caked or become conglomerated. The forward ow of the Vmaterial is interrupted in the intermediate mixing chamber or chambers 16 and the partially dried material is more intimately mixed. The said mixing chamd ber or chambers is-tted with a series of e partially dried material round and dischar e the same by cascadin it on to the baille 4,gbreaking up any materiali which may have cakd'rbecome congealed. The said baiile may, as before stated, consist buckets or scoops 20, as hereinbefore stated,

of a truncated cone and may have vanes 5 attached thereto, which Yanes would assist in the disintegration of any caked material and also guide the flow of said material along the baille 4. These vanes 5 may be so formed and arranged :that the partially dried material is' caused to follow a track, other than one parallel to the baille, and be thus subjected to a longer period of heat impingement by the hot gases before discharge therefrom. The material direction by the baille 4, passes into the next undivided portion of the drum 3 and is again divided in the internal cells 2l and carried forward, by reason of inclination of same, to the discharge end of the drier, being removed therefrom by means of a chute or conveyor 17.

If more than one intermediate chamber 16 is used the operations above described may be repeated until the material reaches the discharge end of the drum or cylinder.

The discharge end of the drum or cylinder may be provided with an opening` communieating with the air, so that fresh atmospheric air can be drawn through the discharge end of the drier, the baille and the tube Q3 and be delivered to the furnace grate in a preheated condition.

l/Vhat I claim is 1. A rotary drying apparatus comprising a rotary drum having end portions of substantially uniform diameter and an inter;

blades.

2.. .A rotary drying apparatus comprising a rotary drum having end portions of unlform diaineter and an intermediate portion providing an'enlarged chamber, each of the end portions being formed to provide an approximately central tube, and partitions radiating therefrom to form material conduits, the central tube at the material discharge yend of the drum being enlarged Within the central chamber in the form of a conical baille having an axial length lef-'s than the similar length of the chamber, the central tube at the material inlet portion of the drum extending to the enlarged end of the conical baiile, the material conduit extending from the inlet end of the drum delivering the material into the enlarged chamber in advance of the conical baiile.

In testimony whereof I have hereunto signed my name.

HORACE ARTHUR MARSTON. 

